1. Field of the Invention
This invention relates to the production and medical use of X-rays, and more particularly to the production, by X-ray micro-tubes, of low energy, highly absorable, polychromatic X-rays and to the use of those X-rays in the treatment of tumors when such X-ray micro-tubes are placed within, or adjacent to, mammalian bodies in very close proximity to, or within, tumors.
2. Description of Related Art
It has been stated that the goal of radiation therapy is to achieve in a selected treatment volume, a dose distribution of radiation that provides the patient with maximum tumor control and the least possible effect on surrounding normal tissues. (PRINCIPLES AND PRACTICE OF RADIATION ONCOLOGY, C. A. Perez, and L. W. Brady, Editors; J. B. Lippincott Company, Philadelphia. 1987 Pg. 159).
To acheive that desired goal, many methods have been advanced over the last 90 or so years which have focused on the use of very high energy sources of radiation. Current radiation treatment of tumors involves the use of large external high energy devices such as X-ray machines, linear accelerators, betatrons, or microtrons, or the use of very high energy emissions from radiosotopes.
The radioisotopes may be placed in large external machines such as .sup.60 Cobalt teletherapy machine, or implanted near a tumor site. Present Applicants are aware of a surgical procedure being utilized in the treatment of brain tumors in which tiny holes are drilled in the skull. The surgeon inserts thin tubes with closed bottom ends into the tumor. Radioactive pellets the size of peas are inserted into the tubes. The implants deliver strong radiation to the tumor. They are removed a few days later.
The safety of these above-identified high energy radiation sources has been a constant concern for health professionals. Not only can the tumor and surrounding normal tissue within the patient be affected by these high energy radiation sources, but the health professionals working near the patient can be adversely affected if adequate safeguards are not taken.
Although the high energy devices have been designed to produce a maximum of antitumor acitivity with a minimal effect on a patient's normal tissues, the side effects of the radiation therapy on the patient's normal tissue can still be the limiting factor in a course of therapy.